Subtractive roller counter



May l0, 1966 F. KUBLER 3,250,467

SUBTRCTIVE ROLLER COUNTER I Filed June 19, 1964 6 Sheets-SheecI 1 Figi m4 May 10, 1966 F. KUBLER 3,250,467

SUBTRACTIVE ROLLER COUNTER Filed June 19, 1964 6 Sheets-Sheet 2 Fig 6 fm/enar: vra-e mf 7026A a QW,

May 10, 1966 F. KBLER 3,250,467

SUBTRACTIVE ROLLER COUNTER Filed June 19, 1964 6 Sheets-ShamI I5 May 1o, 1966 F. KBLER 3,250,467

SUBTRACTIVE ROLLER COUNTER Filed June 19, 1964 6 Sheets-Sheet 4 Figa l1 20 May l0, 1966 F. KUBLER 3,250,457

SUBTRACTIVE ROLLER COUNTER Filed June 19, 1964 6 Sheets-snee?I 5 3,/ L n 31 I! l l M 'mi M H 1 35 1 1 4 i I l /l 35 l i I I y y l L L l l lm/enor.' '73% M fina/f,-

May 10, 1966 F. KUBLER 3,250,467

SUBTRACTIVE ROLLER COUNTER Filed June 19, 1964 6 Sheets-Sheet 6 El* Fig. m Fig.

United States Patent O 3,250,467 SUBTRACTIVE ROLLER CUNTER Friedrich Khler, Hahnstrasse 8, Schwenningen (Neckar), Germany Filed .lune 19, 1964, Ser. No. 376,487 Claims. (Cl. 23S- 132) The present invention relates to a counter mechanism 'with a plurality of axially arranged numeral wheels coupled to each other by a tens transfer mechanism. These numeral wheels are adapted to be adjusted to a ldesired preselected number and, starting from this number, are, in a subtracting operation, turned back in steps toward zero by one unit with each of the operations to be counted, for instance by electr-ic impulses. When the zero position has been reached, a control operation,

`for instance in electric control operation, will be initiated.

With heretofore known counting mechanisms of the above-mentioned type, the numeral wheels, which are subdivided into ten units, carry on their circumference numbers from zero to 9 and are coupled with an adjacent numeral wheel by means of a tens transfer transmission tin such a way that the numeral wheel indicating the neXt higher adjusting value is turned back by one unit when the numeral wheel with the lower digit, following a complete revolution, is turned to the numeral 9. When Iall operations to be counted in conformity with the adjusted number have been completed so that the wheels have reached their zero position, or, assuming a live-digit counter mechanism, are turned from 00 000 to 99 999, a control signal is initiated, for instance a lever or electric Contact is actuated. By pressing upon a 4lever or a key, the numeral wheels may be reutrned to the preselected number, so that a new series of coun-ting operations can be initiated or a cycle can be repeated.

For purposes of selecting and setting a desired preselected number, with heretofore known embodiments of preselectors of the type involved, a special gear is coupled with the numeral wheels, said gear meshing with a gear connected to the numeral wheel. This adjusting gear is accessible after opening a lid. According to one heretofore known design, the setting gear is actuated from the outside by a rotatable knob or by a key. Moreover, also, preselectors have become known according to which the numeral wheels, following the opening of a lid covering the numeral wheels, can be manually set directly by turning.

It is an object of the present invention to provide an adjustable preselector which, while having its dimensions greatly reducedover those of heretofore known devices of the type involved, can be produced in a close design and, when built into switchboards and the like, can easily be actuated from the outside.

It is another object of this invention to provide means which will prevent accidental change in the setting of the selected starting number.

These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawings, in which:

FIGURE 1 illustrates a vie'w of a counter according to the present invention;

FIGUR'E 2 shows the device of FIG. l as seen from the top;

4FIGURE 3 illustrates a side View of the device of FIGURE 1; 5

FIGURES 4 and 6 respectively illustrate a front view (and side view of a numeral wheel with the gear pertaining thereto and a heart-shaped cam;

FIGURE 7 illustrates, partially in section, on a greatly enlarged scale, a key for setting theapparatus, said 3,250,467 Patented May 10, 1966 section being taken along the line VII-VII of FIG URE'l; 'i

FIGURE 8 is a partial section similar to that of FIG- URE 7 but showing the key in working position;

lFIGURE 9 is a section along the line IX-lX of FIG- URE 1 showing in section three keys of the preselector counter. l

FIGURIE 10 isa front view of a numeral wheel with a pawl-ratchet mechanism according tothe present invention.

FIGURE 1-1 is a section taken along the line XI--XI of FIG. l0.

FIGURE `l2 is a top view of FIG. l0.

As stated above, the present invention is directed to a numeral wheel counter mechanism of the above-men- -tioned general type in which each numeral wheel has associated therewith a lkey adapted to be pressed for adjusting or setting a numeral wheel equipped with a heartshaped cam to the preselected number. The present invention is characterized primarily in that each key has an vabutment and a key lever which, when being depressed, tangentially enters into the range of a gear ring of a numeral wheel and, while doing so, turns the numeral wheel relative to the heart-shaped cam held stationary, by an angle corresponding at least to one unit.

According to a further development of the present invention, the keys arranged in a row parallel to theiaxis of the numeral wheels are covered by an arm of a preferably -two-arm lsafety lever which is adapted to be tilted about an axis parallel to the direction of movement of the keys. These safety levers may be so designed that they can be moved into a key releasing position only when the respective numeral rollers associated therewith are disconnected from the respective heart-shaped cam pertaining thereto for returning the numeral wheels to a position corresponding to the preselected number.

lf the safety lever has its aXis of rotation arranged adjacent a return key by means 'of which lthe numeral Wheels may be returned by heart-shaped cams to the preselected number while being disengaged from the heartshaped cams, it is possible, without ditliculties, so to design the second shorter arm of the two-arm safety lever, that the safety lever can be tilted into its key releasing position when simultaneously the return or resetting key is depressed and the shorter lever arm, by means of the depressed resetting key, has been tilted, and the return key can be held in its depressed position.

Referring now to the drawings in detail, the preselector counter according to the invention, generally designated 1, has been designed as an in'sertable unit for insertion into a switchboard or the like. Counter 1 has a front plate 10 with a rectangular window opening 11 behind which there are arranged ve adjacent numeral wheels 12 which are axially aligned and rotatable about a common axis. Each of the numeral wheels 12, of which one is shown in FIGS. 4 to 6 in different positions, has at its circumference ten numbers from Zero to 9 and is connected to a gear 13 which Ahas twenty teeth and is mounted on one of the two faces of the numeral wheel.v On the other end face of each numeral wheel there is provided a heart-shaped cam disc 14 Which is coupled with a numeral wheel through the intervention of a pawlratchet mechanism as illustrated in FIGS. 10 to 12. This paWl-ratchet mechanism comprises two levers 45 rotating together with the heart-shaped disc 14. Levers 45 are pivotally lsupported by studs 46 connected to disc 14. Each lever 45 is provided with a circular cam 45a adapted to engage segment-shaped recesses 45b in numeral wheel 12. Helical springs 47 concentrically arranged on studs 46 continuously urge the levers 45 into locking position. One leg 47a ofhelical spring 47 rests against a bolt 48 xedly connected to lever 45 while the other one rests against hub 12a of wheel 12.

Numeral wheel 12 is additionally provided with two follower studs 15 and 16 (FIGS. 6 and l0). Each time, following-a complete revolution of the respective numeral wheel with a lower digit, these studs turn the respective adjacent numeral wheel of a digit higher by one unit than said lower digit, by one unit of adjustment. This turning movement is in the direction toward zero.

The actuation of the counter mechanism is effected by an electromagnet 19 indicated in FIG. l by dash-lines. The armature of electromagnet 19 is moved into its starting position by electric impulses conveyed to the electromagnet while the numeral wheel, shown in FIG. l as the outermost fright-hand wheel, is each time moved by -a pitch of the gear 13 and thus by half a number. When the armature thereupon drops off, the numeral wheel is rotated by the remaining half of the number.

Near the left-hand narrow side of the window opening 11 there is provided a return key or resetting key 20 of rectangular cross-section. This key 20 is, through the intervention of an intermediate lever 21 (see FIGS. 7 and 8) coupled to a shaft 22 which is parallel to the axis of rotation of the numeral wheels. Shaft 22 arries live resetting levers 23 which are arranged one behind the other in spaced relationship to each other.

Each of the resetting levers 23 is associated with one of the iive numeral rollers and has its free end provided with an approximately circular disc-shaped engaging head 24. When the return key 2t) is pressed from its FIG. 7 rest position in the direction of the arrow D into the working position illustrated in FIG. 8, the resetting lever 23 tilts toward the axis of rotation of the numeral wheels 12 and thus presses strongly against the heart-shaped cams 14, so that the latter turn until the engaging head 24 of the resetting lever 23 engages a setting groove 25 of the respective heart-shaped cam disc pertaining thereto. During this tilting movement of lever 23 for resetting the heart-shaped cam disc 14, simultaneously the tens transfer drive 18 disengages the numeral wheels so that the latter can be carried along by the heart-shaped cams when the latter return to their starting position. More specilically, with regard to FIGS. l0 to l2, the heart-shaped cam disc 14 carries along numeral wheels 12 through the intervention of the pawl-ratchet mechanism 45 to 48. If the numeral wheels 12 are in engagement with the tens transfer drive 18 and if disc 14 moves relative to the numeral wheels 12, the levers 45 automatically move out of the recesses 45h of wheel 12 against the thrust of the springs 47. When all of t-he heart-shaped cams have been returned to such an extent that the resetting lever 23 pertaining thereto has the head 24 thereof in engagement with t-he recess 25, all of the heart-shaped cams 14 occupy the same position relative to each' other and to `the tens transfer mechanism 18. The number then indicated by the ve numeral wheels 12 depends on the angle of rotation by which the numeral wheels have been adjusted relative to the tip or point of the heart-shaped cam. In this position, the numeral wheels are held relative to the heart-shaped cam disc by means of pawlratchet mechanism 45 to 48.

In order .to be able to turn each of the ive numeral wheels in a simple manner and relative to the heartshaped cam disc 14 pertaining thereto so that the ve numeral wheels indicate the desired preselected number between zer-o and 99 999, in conformity with lthe present invention, each of the numeral wheels 12 has associated therewith one of the live keys 3i). Each key has associated therewith an abutment 38 and a setting key 31 which, against the thrust of a hel-ical spring 32, can be pressed inwardly to such an extent that they enter ,the tooth range of gear 13 of the respective adjacent numeral wheel. The lactuation of the setting keys 31 may be effected, for instance, by means of setting pins 4 34 guided in guiding eyes forming part of the front plate 1t). The setting keys 31 will, during this setting operation, be guided in longitudinal slots 35 of a guiding member 36 and will be pressed `against the ygear ring by means of a leaf spring 37 screwed onto the guiding member 36. The stroke of insertion of the setting key 31 is, by abutment 3S at the upper end of the setting key, limited in such a way that the setting key 31 will with each complete stroke during its pressing-in movement, be able to turn gear 13 only by twicev the pitch of said gear i13 which, during this turning movement, disen-gages the pawl-ratchet mechanism against a strong thrust and will engage the next engaging position corresponding to the next higher number while the heart-shaped cam disc 14 is held stationary. In this way, each of the numeral wheels may be adjusted or set for the desired number appearing at the window cut-out 11. Each numeral wheel will, following the completion of the setting operation, remain in its respective adjusted angular position relative to the respective heart-shaped cam disc pertainin-g thereto, as soon -as the return key 20 has been released and, by means of a return spring, is returned to its FIG. 7 starting position.

With the above-described setting operation, the gear of numeral wheel 12 rotates in the direction indicated by the arrow E relative to the heart-shaped cam disc 14 which is held stationary by the reset-ting lever 23. During these operations, in window cut-out 11 there will succes-sively appear figures increasing by one unit each, for instance, lirst the num-ber 2, then the number .3, then the number 4, etc. During Ithe registering operation of the control impulses conveyed to the electromagnet (19, ,that numeral Wheel 12 which is adjacent to the electromagnet will turn in -a counter-clockwise direction, viz. the direction indicated by the arrow L, while following each control impulse, a number will be indicated which is lower than the previous number by one unit.

In order to assure that the keys 30 and resetting keys 31 Will Ibe actuated only when Simultaneously also the resetting key 2? has been depressed, there is provided above keys 30 a safety lever 40 illustrated in FIG. 1 in full-lines and shown in a position 4in which it covers the keys 30 thereby preventing actuation of the keys 30 and 31. The safety lever 4t) is designed as a two-arm lever the shorter arm 41 of which is located in direct proximity to the return'key 20, and engages the same when arm y41 is turned counter-clockwise out of its full-line or covering or barring position. Only when the return key 20 `is moved into its FIG. 8 position in -which the return lever 23 engages the grooves 25 of the heart-shaped cam discs 14, will it be possible to move the safety lever into the dash-line position of FIG. l. The short arm 41 of safety lever 46 will then extend above that end of return key 20 which protrudes beyond the front plate .10 and holds fast return key 20 for the duration of the now possible adjustment for the new number -to be preselected, in such a way that when `resetting 1keys 31 are depressed, the numeral wheels i12 can be adjusted relative to their respective heart-shaped cams ,14. As soon as the safety lever 40 has been tilted back to its starting position illustrated in solid lines, the new subtractive counting operation may now be eifected from the now adjusted preselected number. At the end of this counting operation, that numeral 12 which is located fanthest toward the left and indicates the highest `digit will actuate a nonillustrated con-trol contact as soon as this numeral wheel is, at the end of the counting operation, being returned from zero to 9. Subsequently, the resetting key 20 has again to be depressed in order that the adjusted preselected number is again obtained, because, upon the depression of return key Ztl, the resetting levers 23 reset the heart-shaped cam disc 14 -to such an extent that said levers can again engage the depressions 25. If the device is not to be setfor a new fpreselected number, the new counting operation can `start immediately. It it is desi-red successively -to carry out a plurality of counting oper-ations starting from one and the same preselected number, it is, of course, also possi-ble to brin-g about the rese-tting of the cam discs 14 and thereby the resetting of the numeral wheels to the preselected number, and to use the resetting key 2G only for holding Ilthe cam discs 14 when the device is to be set for a new preselected number.

Safety lever 40 will assure that when setting the device for a new preselected number, the operation will lbe pos-sible only in the prescribed sequence. In this way, disturbances by faulty operations, will be avoided. In order to 4assure that the safety lever 41 will automatically rem-ain in its dash-line position of FIG. 1

in which it frees the keys 30 forl setting a new preselected number, i-t is possible to provide an undulated spring disc 43 below the connecting screw 42 which simultaneously serves as a pivot in such a way that setting disc 43 will be clamped against the head screw and will press the safety lever40 against the front plate 10. However, it is more advantageous to provide a cam 44 protruding 'from the inner surface of lever 40 and adapted to engage the opening formed by the guiding eye 13-3 whereby lever 40 is arrested in its dash-line position of FIG. 1. Disc 43 serves primarily as a resilient compensation for machining tolerances when re- Nsetting key 20 is depressed.

'It is advantageous to design the guiding member 36 convexly curved, in conformity with the numeral wheel 12, and to rest spring 37 by a screw connection on the guiding member 36. In order to obtain a simple supportfor the helical spring 32, the guiding member 36 is curved in such a way that it rests against the lower end of the guiding eye 33 (see FIG. 7)..v This portion 36a of the guiding member 36 simultaneously forms guiding means for key 31 inasmuch as in the bent portion 36a there is provided a slot 35a through which extends key 31 in such a way that its end face 31a, due to the thrust of leaf spring or the like 37 rests against a guiding edge 35 of recess 35a. .i The resetting of control key 31 is effected by spring 32 which has an end winding resting against the abutment 38 while its other end winding rests lagainst a bent portion 36a of the guiding member 36.

It is, of course, to be understood, that the present in-,

vention is, by nomeans, limited to the particular constructions shown in the drawings, but also comprises any modifications within the scope of the appended claims. Thus, instead of providing an electric drive for the counting mechanism, the counting mechanism may, of course, also be driven mechanically by a rotating shaft or by a reciprocable movement. The electric drive m-ay be so designed that each impulse adjusts an entire number and that the armature, when disengaging itself, will be reset withou-t actuating a unit or that the armature, when being attracted, will not actu-ate a unit but will do so only when disengaging itself.

What I claim is:

1. In a counter wheel system comprising; a frame and a plurality of axially aligned counter wheels in said frame, said wheels having teeth and having member units indicated thereon, tens transfer means interposed between said counter Wheels, coupling means for coupling said tens transfer means to said counter Wheels; cam means for resetting said counter wheels and respectively connected to said counter wheels so the Wheels can be rotative'ly adjusted relative to their respective cam means, a key in said frame associated with each said counter wheel extending in a direction substantially tangentially I counter wheel pertaining thereto and to move the latter through an angle corresponding to at least a unit on the respective counter wheel, a single means for holding said cam means stationary in the position in which said wheels are reset during movement of said wheels by their respective keys, a resetting member operable to actuate all of said cam means to reset said counter wheels, and a cover member moveable between a rst position wherein it covers all of said keys and a second position wherein it uncovers all of said keys, said cover member being operable when in said second position to engage and hold said resetting member in actuated position.

2. In a counter wheel system comprising; a frame and a plurality of axially aligned counter wheels in said frame, said wheels having teeth and having number units indicated thereon, tens transfer means interposed between said counter wheels, coupling means for coupling said tens transfer means to said counter wheels; cam means for resetting said counter wheels and respectively connected to said counter Wheels so the Wheels can be rotatively adjusted relative to their respective cam means, a key in said frame associated With each said counter wheell extending in a direction substantially tangentially of the pertaining counter wheel and selectively longitudinal-ly movable into the range of the said teeth of the respective counter Wheel, each of said keys being operable directly to engage the respective adjacent tooth of the counter Wheel pertaining thereto and to move the latter through an angle corresponding to at least a unit on therespective counter Wheel, means for holding said cam means stationary in the position in which said wheels are reset during movement of said wheels byl their respective keys, said keys being in a row, a resetting plunger projecting from said frame at the end of said row of keys'and depressable for actuating said cam means into wheel resetting position, and a lever pivoted to said frame and having a rst portion adapted for covering said keys and a second portion adapted for engagement with said resetting plunger when the latter is in depressed position, said second portion engaging said resetting plunger When said lever is adjusted so said one portion uncovers said keys and disengaging said resetting plunger when said lever is adjusted to said one portion covers said keys.

l3. A counter wheel system according to claim 2 in which said second portion of the rlever abuts said resetting plunger and prevents movement of said lever to key uncovering position prior to depressing of said plunger.

4. A counter wheel system according to claim 3 in which said frame comprises recess means in which said tens transfer means to said counter wheels; cam means for resetting said counter wheels and respectively connected to said counter wheels so the wheels can be rotatively adjusted relative to their respective cam means, a key in said frame associated with each said counter wheel extending in a direction substantially tangentially of the pertaining counter wheel and selectively longitudinally movable into the range of the said teeth of the respective counter wheel, each of said keys being operable directly to engage the respective adjacent tooth of the counter wheel pertaining thereto and to move the latter through an angle corresponding to at least a unit on the respective counter wheel, a single means operable for engaging and holding said cam means stationary in the position in which said wheels are reset during movement of said Wheels by their respective keys, and a curved guiding plate in the frame adjacent said counter wheels and concave on the side toward said counter wheels and slotted to receive each of said keys, and a spring on said guide p'late for each key resiliently urging its respective key toward the adjoining counter wheel.

6. A counter Wheel system according to claim 5 in which each guiding plate has its upper end bent over, a helical spring bearing at one end on top of said bent over end, and an abutment on the pertaining key beneath which the other end of the helical spring bears t bias the key toward retracted position.

7. A counter wheel system according to claim 6 in which said frame comprises a tubular means in which each of said keys are disposed for selective actuation by a rod-like element, and a shoulder in said tubular means positioned to be engaged by said abutment when the key is retracted.

8. A counter wheel system according to claim in which each guiding plate is slotted to receive the pertaining key and a spring on each guide plate resiliently urging the pertaining key toward the respective counter Wheel, each of said keys being bar-like and havingan end in the slot of the guide plate pertaining thereto and engaged by the spring pertaining thereto, the upper end of each guide plate being bent over and apertured to receive the key pertaining thereto, and the aperture in each bent-over portion having an end surface on which the key slidably rests.

9. In a counter wheel system comprising; a frame and a plurality of axially aligned counter wheels in said frame, said wheels having teeth and having number units indicated thereon, tens transfer means interposed between said counter wheels, coupling means for coupling said tens transfer means to said counter Wheels; cam means for resetting said counter Wheels and respectively connected to said counter Wheels so the Wheels can be rotatively adjusted relative to their respective cam means, a key in said frame associated with each said counter wheel extending in a direction substantially tangentially of the pertaining counter wheel and selectively longitudinally movable into the range of the said teeth of the respective counter Wheel, each of said keys being operable directly to engage the respective adjacent tooth of the counter wheel pertaining thereto and to move the latter through an angle corresponding to at least a unit on the respective counter wheel, a single means for holding said cam means stationary in the position in which said Wheels are reset during movement of said Wheels by their respective keys, each key being accessible from outside said frame, each cam means comprising a heart-shaped cam, a resetting shaft in the frame, a lever on theshaft for engaging each cam when the shaft is rotated whereby all of the Wheels can be reset at one time, a plunger projecting from the frame adjacent said keys and connected to the shaft and dependable for actuating the shaft into Wheel resetting position, and interlock means on the frame adjacent said keys and plunger operable for permitting actuation of said keys only when said plunger is depressed.

10. In a counter Wheel system comprising: a frame and a plurality of arially aligned counter wheels in said frame, said Wheels having teeth and having number units indicated thereon, tens transfer means interposed between said counter Wheels, coupling means for coupling said tens transfer means to said counter Wheels; cam means for resetting said counterwheels and respectively connected to said counter Wheels so the Wheels can be rotatively adjusted relative to their respective cam means, a key in said frame associated with each said counter Wheel extending in a direction substantially tangentially of the pertaining counter Wheel and selectively longitudinally movable into the range of the said teeth of the respective Wheel, each of said keys being operable to engage the respective adjacent tooth of the counter Wheel pertaining thereto and to move the latter through an angle corresponding to at least a unit on the respective counter Wheel, means for holding said cam means stationary in the position in which said wheels are reset during movement of said Wheels by their respective keys, said keys being in a row, a resetting plunger projecting from said frame at the end of said row of keys and depressable for actuating said cam means into Wheel resetting position, a liever pivoted to said frame having one end for covering said keys and another end engageable with said resetting plunger when the latter is in depressed position and said lever is in key uncovering position, a recess in l the frame for each key, detent means on the lever engageable with one of said recesses, and spring means biasing said lever toward said frame to hold said detent means releasably in said one recess.

References Cited by the Examiner UNITED STATES PATENTS 2,137,013 11/1938 Bradley 235--132,1 2,920,816 1/1960 Greenhow 23S-1.3 3,057,553 10/1962 Billeter 23S- 132 3,064,893 11/1962 Grinstead 23S-144 LOUIS I. CAPOZI, Primary Examiner.

LEO SMILOW, Examiner.

C. G. COVELL, J. G. MURRAY,

Assistant Examiners. 

1. IN A COUNTER WHEEL SYSTEM COMPRIISNG; A FRAME AND A PLURALITY OF AXIALLY ALIGNED COUNTER WHEELS IN SAID FRAME, SAID WHEELS HAVING TEETH AND HAVING MEMBER UNITS INDICATED THEREON, TENS TRANSFER MEANS INTERPOSED BETWEEN SAID COUNTER WHEELS, COUPLING MEANS FOR COUPLING SAID TENS TRANSFER MEANS TO SAID COUNTER WHEELS; CAM MEANS FOR RESETTING SAID COUNTER WHEELS AND RESPECTIVELY CONNECTED TO SAID COUNTER WHEELS SO THE WHEELS CAN BE ROTATIVELY ADJUSTED RELATIVE TO THEIR REPSECTIVE CAM MEANS, A KEY IN SAID FRAME ASSOCIATED WITH EACH SAID COUNTER WHEEL EXTENDING IN A DIRECTION SUBSTANTIALLY TANGENTIALLY OF THE PERTAINING COUNTER WHEEL AND SELECTIVELY LONGITUDINALLY MOVABLE INTO THE RANGE OF THE SAID TEETH OF THE RESPECTIVE COUNTER WHEEL, EACH OF SAID KEYS BEING OPERABLE DIRECTLY TO ENGAGE THE RESPECTIVE ADJCENT TOOTH OF THE COUNTER WHEEL PERTAINING THERETO AND TO MOVE THE LATTER THROUGH AN ANGLE CORRESPONDING TO AT LEAST A UNIT ON THE RESPECTIVE COUNTER WHEEL, A SINGLE MEANS FOR HOLDING SAID CAM MEANS STATIONARY IN THE POSITION IN WHICH SAID WHEELS ARE RESET DURING MOVEMENT OF SAID WHEELS BY THEIR RESPECTIVE KEYS, A RESETTING MEMBER OPERABLE TO ACTUATE ALL OF SAID CAM MEANS TO RESET SAID COUNTER WHEELS, AND A COVER MEMBER MOVEABLE BETWEEN A FIRST POSITION WHEREIN IT COVERS ALL OF SAID KEYS AND A SECOND POSITION WHEREIN IT UNCOVERS ALL OF SAID KEYS, SAID COVER MEMBER BEING OPERABLE WHEN IN SAID SECOND POSITION TO ENGAGE AND HOLD SAID RESETTING MEMBER IN ACTUATED POSITION. 